Automatic weight-responsive container fillers



W. L. ESPENSCHIED ETAL Feb. 28, 1967 3,306,382

' AUTOMATIC WEIGHT-RESPONSIVE CONTAINER FILLERS Filed Feb. 5, 1965 2 Sheets-Sheet 1 ON SWITCH SOLENOID COIL Fig. 5

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AUTOMATIC WEIGHT-RESPONSIVE CONTAINER FILLERS Filed Feb. 5, 1965 2 Sheets-Sheet 2 Fig. 7

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ATTORNEYS United States Patent Ofiice 3,306,382 Patented Feb. 28, 1967 3,306,382 AUTOMATIC WEIGHT-RESPONSIVE CONTAINER FELLERS Wilbur L. Espenschied and John A. Maurer, Canton, Ohio, assignors to The Weber Dental Manufacturing Company, Canton, Ohio, a corporation of Ohio Filed Feb. 5, 1965, Ser. No. 430,539 2 Claims. (Cl. 177117) Our invention relates to improved automatic container filler construction for use on dental units and the like, and more specifically, to automatic container fillers which are actuated through the placing of a container thereon, and are arranged for automatically filling the container with water to a generally predetermined level. Even more specifically, our invention relates to the foregoing type of automatic container filler incorporating improvements adapted for preventing the supply of water to the filler from being re-opened, even momentarily, after the container has been filled to the predetermined level and during the removal thereof from the filler.

Certain prior constructions of automatic container fillers have been provided in which the placing of a container thereon, usually a paper cup positioned in a metal cup holder, automatically actuates an electric water solenoid valve for admitting water from a water supply line into the container. Furthermore, these prior constructions have been arranged so that when the container is filled to a generally predetermined level, the water sole noid valve is automatically closed to close off the supply of water to the container.

At least some forms of these prior constructions have accomplished this by the provision of normally open and normally closed snap-action switches electrically connected in an electrical circuit with the water solenoid valve, and positioned relative to a container platform of the filler so that when the container platform is in an upper position in which no container is present thereon, the normally open switch remains open and the normally closed switch remains closed.

When a container is placed on the cup platform, this cup platform, as the result of the weight of the container and a metal container holder, moves downwardly into an intermediate lower position which causes actuation of the normally open switch for movement of this switch to closed position, while the normally closed switch remains non-actuated and in closed position. The closing of the normally open switch completes the electrical circuit through the normally closed switch and water solenoid valve, opening this valve and starting the flow of water into the container.

When the container has filled to the generally predetermined level, the increased weight caused by the water within the container results in the container platform being moved slightly further downwardly to a position in which the normally open switch, which was previously actuated and closed, remains closed, but the normally closed switch is now actuated and moved to open position. This opens the electrical circuit through the switches and water solenoid valve, thereby closing the valve and stopping the flow of water into the container, with the circuit remaining in this condition as long as the filled container remains on the container platform.

The principal difficulty with this prior form of automatic container filler construction is that, although removal of the filled container from the container platform results in this container platform automatically moving from this lower container-filled position upwardly to the upper no-container position, and although this results in the normally open and normally closed switches being returned to the original positions wherein the normally open switch maintains the electrical circuit open and,

therefore, the solenoid water valve closed, this container platform must move through the intermediate position in this path of movement from the lower position to the upper position. With the electrical circuit and switch arrangement described, this causes the electrical circuit through the solenoid water valve to be closed for an instant during such return movement of the container platform as a consequence of the normally closed switch being released to close prior to the normally open switch being released to open, that is, merely a reversal of the switch actuation during the downward movement of the cup platform.

The ultimate result of this action inherent in this automatic container filler arrangement is that when the container is removed from the container platform, a spurt of water is emitted from the water line during this short interval of upward movement of the container platform to its original upper position. Where the automatic container filler is incorporated, for instance, in a dental unit, this cannot only frighten a patient due to the startling nature thereof, but it likewise can be irritating from the standpoint of causing water to splash on the patients hand and clothes.

It is, therefore, a general object of the present invention to provide automatic container fillers for dental units and the like which eliminate the foregoing difficulty in a relatively simple manner.

It is a primary object of the present invention to provide automatic container fillers for dental units and the like which automatically fill the container with water to a generally predetermined level and automatically shut off the water supply at this predetermined container level, yet when the container is removed from the container platform, there is no resulting spurt of water from the water line as in the prior constructions.

It is a further object of the present invention to provide automatic container fillers for dental units and the like in which the placing of the container on a container platform depresses the container platform to a position in which a supply of water to the container is automatically turned on, the filling of the container to a generally predetermined level depresses the container platform a further extent to a position in which the supply of water is automatically shut off, and during the subsequent removal of the filled container and the return of the container platform upwardly to original no-container position, the supply of water from the water line will remain completely off.

It is still a further object of the present invention to provide automatic container fillers for dental units and the like in which an electric solenoid water valve and switch means are operably connected with an electrical circuit for automatically filling the container with water to a generally predetermined level when the container is placed thereon, and which includes unique holding means operably arranged with one of the switch means and electrical circuit for maintaining the water valve closed during and after the removal of the filled container therefrom, and until the container filler has returned to a no-container condition.

Finally, it is an object of the present invention to provide automatic container fillers for dental units and the like which satisfy all of the above objects in a relatively inexpensive and efiicient manner, at least one form of which may be simply incorporated in previously existing constructions.

These and other objects are accomplished by the parts, constructions, arrangements, combinations and subcombinations comprising the present invention, preferred embodiments of whichillustrative of the best modes in which applicant has contemplated applying the principles-are set forth in the following description and illustrated in the accompanying drawings, and which are particularly and distinctly pointed out and set forth in the appended claims forming a part hereof.

In general terms, the improvements in automatic container fillers for dental units and the like may reside in a container filler construction of the type in which a container platform upon which a container may be positioned is mounted on a frame for movement of the container platform between an upper first position downwardly to an intermediate second position and further downwardly to a lower third position, with the container platform being normally biased to the upper first position in the absence of a container being positioned thereon. Further, the container filler may be of the type in which the container platform will move from upper first to intermediate second position as the result of the container being positioned thereon, and will move to the lower third position as the result of the container being filled with water to a generally predetermined level.

In such construction, the water for filling the container may be received from a water line mounted positioned for directing water into the container when the container is positioned on the container platform. Also, the water line preferably includes a water valve normally biased to closed position and electrically actuated to open position so that the water will be directed from the water line into the container when this water valve is electrically actuated to open position.

According to the improvements of the present invention, the container filler construction includes an electrical circuit operably connected through the water valve, actuating the valve to open position upon the electrical circuit being closed and permitting the valve to be biased to closed position upon the electrical circuit being opened, with switch means operably connected in the electrical circuit and switch actuating means operably connected between the container platform and switch means for actuating the switch means upon movement of the container platform. Further, the switch means is constructed and arranged for opening the electrical circuit when the container platform is in upper first position, for closing the electrical circuit when the container platform is moved from upper first to intermediate second position, and for opening the electrical circuit when the container platform is moved from intermediate second to lower third position.

\Finally, the improvements include means operably arranged with either one or both of the switch means and electrical circuit for maintaining the electrical circuit open and, therefore, the water valve biased to closed position during the reverse movement of the container platform from lower third to upper first position. Such means may be in the form of relay means operably connected in the electrical circuit for actuation through the electrical circuit and switch means at least when the container platform is moved from intermediate second to lower third position, and for maintaining the electrical circuit open during movement of the container platform from lower third to upper first position. Also, such means may be in the form of means operably connected to and actionable on the switch means at least during movement of the container platform from lower third to upper first position for maintaining the electrical circuit open during such movement.

Thus, with the improved automatic container filler construction of the present invention, the placing of a container on the container platform will move the platform from upper first to intermediate second position to open the watervalve and begin the flow of water into the container, the filling of the container will move the container platform from intermediate second to lower third position to close the water valve and stop the flow of water into the container, and removal of the filled container from the container platform will permit the platform to return from lower third to upper first position while the water valve remains closed.

By way of example, embodiments of the improved automatic container filler construction of the present invention are illustrated in the accompanying drawings forming a part hereof, wherein like numerals indicate similar parts throughout the several views, and in which:

FIG. 1 is a fragmentary vertical sectional view, part in elevation, of an automatic container filler incorporating the improvements of the present invention, according to a first embodiment thereof, with a filled container positioned on the container platform and the platform depressed to the lower third position;

FIG. 2, a fragmentary sectional view, part in elevation, looking in the direction of the arrows 22 in FIG. 1;

FIG. 3, a fragmentary vertical sectional view similar to FIG. 1 but with the container removed and the container platform in the upper first position;

FIG. 4, a fragmentary vertical sectional view similar to FIG. 1 but with an unfilled container on the container platform and the platform depressed to the intermediate second position;

FIG. 5, a somewhat schematic Wiring diagram of the automatic container filler of FIG. 1 and showing the switches and relay in position resulting from the container platform being in the upper first position shown in FIG. 3;

FIG. 6, a view similar to FIG. 5 but with the switches and relay in the positions resulting from the container platform being in the lower third position as shown in FIG. 1;

FIG. 7, a somewhat schematic wiring diagram of a slightly modified embodiment of the automatic container filler of FIGS. 1 through 4, and showing a 3-position switch in the position resulting from the container platform being in the upper first position as shown in FIG. 3;

FIG. 8, a view similar to FIG. 7, but showing the 3- position switch in the position resulting from the container platform being in the intermediate second position shown in FIG. 4;

FIG. 9, a view similar to FIG. 7, but showing the 3- position switch in the position resulting from the container platform being in the lower third position shown in FIG. 1; and

FIG. 10, a view similar to FIG. 7, but showing the 3- position switch moving from the position of FIG. 9 back to the position of FIG. 7 resulting from the container platform moving from the lower third position shown in FIG. 1 back to the upper first position shown in FIG. 3 upon the removal of the filled container therefrom.

Referring to FIG. 1, the first embodiment of the automatic container filler construction incorporating the principles of the present invention includes a dental unit frame, generally indicated at 20, a container platform, generally indicated at 21, a pivotal supporting arm, generally indicated at 22, switch means, generally indicated at 23, a relay, generally indicated at 24, a water supply line, generally indicated at 25, and an electrically actuated solenoid water valve, generally indicated at 26. As further shown, the switch means 23 in this first embodiment is formed by the on switch 27 and off switch 28, both of which, and the relationship thereof to this construction, will be described hereinafter more in detail.

The container platform 201 is formed by the generally horizontally positioned perforated disc 29 having a cylindrical hub 30 which threadably receives the spring adjustment screw member 31. The adjustment screw member 31 is formed with the adjustment slot 32 exposed upwardly of the disc 29, and the lower end of this screw member is formed for receiving the upper end of a coil compression spring 33, the lower end of which spring is received over the spring positioning member 34 formed at the lower wall 35 of a drain sump 36.

In addition to the compression spring 33, the container platform 21 is supported secured to the forward end 37 of the supporting arm 22 with this supporting arm being pivotally connected intermediate the ends thereof through the pivot pin 38 to the frame 20. The supporting arm 22 is formed at the rearward end 39 with the cross-bar 40 which, in turn, threadably adjustably mounts the spaced switch engagement members 41 and 42.

The on and off switches 27 and 28 are positioned on the frame 20 with the actuating plunger 43 of on switch 27 aligned for engagement by the switch engagement member 41 and the actuating plunger 44 of off switch 28 alignedfor engagement by the switch engage ment member 42. Thus, downward pivotal movement of the container platform 21 will cause the pivotal supporting arm 22 to move the switch engagement members 41 and 42 against and depressing the actuating plungers 43 and 44 of the on and off switches 27 and 28.

Container platform 21 is biased or resiliently urged upwardly by the coil compression spring 33 to an upper first position when a container is not positioned thereon, as shown in FIG. 3. In addition, the on and off switches 27 and 28 are miniature snap-action switches of usual construction in which actuating plungers 43 and 44 thereof are resiliently urged outwardly to a non-actuating position, so that these actuating plungers 43 and 44, depending on the particular switch construction, may supplement the resilient urging of the compression spring 33 through a resilient urging engagement against the switch engage ment members 41 and 42, and, in certain cases of construction of these switches, may even serve as the sole means for resiliently urging the container platform 21 to this upper first position shown in FIG. 3.

This upper first position of the container platform 21 is exactly determined by the stop shoulder 45 on the supporting arm 22 moving upwardly and engaging the abutment surface 46 on the frame 20, again as shown in FIG. 3. Further, in the particular form of construction illustrated, the compression on compression spring 33 may be selectively regulated by engagement of a tool, such as a screw driver, with the adjustment slot 32 of the adjustment screw member 31 for moving this adjustable screw member upwardly and downwardly relative to the hub 30, to thereby decrease or increase the resilient upward urging of the container platform 21.

The various components of construction described in the foregoing are formed, arranged and adjusted such that when a usual drinking cup or container 47 positioned in the usual metal container holder 48 is positioned on the container platform 21, with such container being empty, the container platform moves downwardly from the above described upper first position to an intermediate second position, as shown in FIG. 4, which, through thepivotal movement of the supporting arm 22, causes the switch engagement member 44 to move the actuating plunger 43 Y of the on switch 27 inwardly, thereby moving this on switch 27 from a non-actuated condition to an actuated condition.

Finally, the various components of construction are formed, arranged and adjusted such that when the container 47 is filled with water to a generally predetermined level, as indicated by the broken line 49 in FIG. 1, this increased weight caused by the water will have moved the container platform 21 from the intermediate second position, as shown in FIG. 4 and previously described, to a lower third position, as shown in FIG. 1. In this lower third position, the actuating plunger 43 of on switch 27 will merely have been moved further inwardly by the switch engagement member 41, retaining this on switch in actuated condition, but switch engagement member 42 will have moved the actuating plunger 44 of off switch 28 inwardly to a position in which the off switch has been moved from a non-actuated condition to an actuated condition.

Thereafter, when the filled container, as shown in FIG. 1, is removed from the container platform 21, this container platform will move upwardly from the lower third position as shown in FIG. 1, through the intermediate second position as shown in FIG. 4, to the upper first position as shown in FIG. 3 and as determined by stop shoulder of supporting arm 22 engaging the abutment surface 46 of frame 20. During this upward movement of the container platform 21, as the container platform leaves the lower third position shown in FIG. 1, the actuating plunger 44 of off switch 28 will be permitted to move outwardly at least sufliciently to move the off switch from actuated to non-actuated condition, and when the container platform 21 has moved upwardly sufliciently to pass above the intermediate second position as shown in FIG. 4, the actuating plunger 43 of on switch 27 will be permitted to move outwardly sufficiently to move the on switch from actuated to non-actuated condition.

To complete the first embodiment construction of the present invention, the water supply line 25, which is of usual construction, is positioned by the frame 20 for directing water into the container 47 when such container is positioned on the container platform 21 and the electrically actuated solenoid water valve 26 is actuated. This solenoid water valve 26 is of usual construction and is operably connected in this water supply line 25 normally biased to closed position and electrically actuated to open position for interrupting or directing the flow of water through the water supply line 25, depending on the position thereof. Also, the usual form of normally off and electrically actuated on relay 24 is mounted on the frame 20 for electrical connection with the solenoid water valve 26, on switch 27, off switch 28 and to an electrical supply source (not shown) in the unique manner shown in FIG. 5 and described below.

The electrical circuit of FIG. 5 includes the supply line 50 to one side of the normally-open contacts 51 of on switch 27, and line 52 from the other side of these contacts 51 to lines 53 and 54. Line 53 is connected to one side of the normally-open contacts 55 of off switch 28 and also to one side of the normally closed contacts 56 of off switch 28, while line 54 is connected to one side of the normally open contacts 57 of the relay 24. I

The other side of the normally open contacts 55 of off switch 28 are connected through line 58 to both the other side of the normally open contacts 57 and one side of the coil 59 of relay 24, with the other side of the relay coil 59 being connected through a line 60 to the supply line 61. The other side of the normally closed contacts 56 of o switch 28 are connected through a line 62 to one side of the normally closed contacts 63 of relay 24 and the other side of these normally closed contacts 63 are connected through line 64 to and through the solenoid coil 65 of solenoid water valve 26.

Solenoid coil 65 of the solenoid water valve 26 is in turn connected to supply line 61 at the point of joinder of this line 61 with line 60. Finally, supply lines 50 and 61 are connected across a usual source of electrical supply, not shown.

Relating the electrical circuit of FIG. 5 to the position of the container platform 21, the on and off switches 27 and 28, and the relay 24. are shown in the condition in which the container platform 21 is in the upper first position with no container 47 positioned thereon. The on switch 27 is in non-actuated condition with the normally open contacts 51 open, the off switch 28 is in non-actuated condition with the normally open contacts 55 open and the normally closed contacts 56 closed, and the relay 24 is in non-energized or non-actuated condition with the normally open contacts 57 open and the normally closed contacts 63 closed.

In view of the fact that the normally open contacts 51 of on switch 27 are open, neither the coil 59 of the relay 24 nor the solenoid coil 65 of solenoid water valve 26 can be electrically energized. Thus, with the container platform 21 in the upper first position as shown in FIG. 3, the solenoid water valve 26 is closed interrupting the flow of water from the water supply line 25.

Still referring to the electrical circuit of FIG. 5, when the empty container 47 with the cup holder 48 are positioned on the container platform 21 as shown in FIG. 4, moving the container platform downwardly to the intermediate second position, the on switch 27 is moved from non-actuated to actuated condition, thereby closing the normally open contacts 51 of the switch. This completes an electrical circuit from supply line 50 through the now-closed contacts 51 of on switch 27, through line 52, through line 53, through the normally closed contacts 56 of off switch 28, through line 62, through the normally closed contacts 63 of relay 24 through line 64, through the solenoid coil 65 of solenoid water valve 26, and to supply line 61, thereby electrically energizing the solenoid coil 65 of water valve 26 and opening this water valve so that water begins to flow from water supply line 25 into the container 47.

Relay 24 at this point is not yet energized since the relay normally open contacts 57 remain open interrupting the electrical circuit to the relay coil 59, and the normally open contacts 55 of the off switch 28 remain open also interrupting the electrical circuit to this relay coil 59.

The water will continue to flow from the water supply line 25 into the container 47 until the water has reached the generally predetermined level 49 shown in FIG. 1. Furthermore, this gradually increasing weight of water in the container 47 will move the container platform 21 further downwardly to the lower third position as shown in FIG. 1.

At this lower third position of the container platform 21, the 011? switch 28 is moved from non-actuated to actuated condition while the on switch 27 remains in actuated condition. Thus, in this lower third position of the container platform 21 and as shown in FIG. 6, the on switch contacts 51 remain closed, the off switch normally open contacts 55 are closed, the off switch normally closed contacts 56 are opened, and the relay coil 59 is energized to close the normally open relay contacts 57 and open the normally closed relay contacts 63.

The energization of the relay coil 59 is accomplished by the closed electrical circuit established from supply line 50 through the closed on switch closed contacts 51, through line 52 and 53, through the off switch nowclosed contacts 55, through line 58, through the relay coil 59, and through line 60 to supply line 61. Energization of relay coil 59 instantaneously closes the relay normally open contacts 57 and opens the relay normally closed contacts 63.

'Thus, as shown in FIG. 6, upon movement of the off switch 28 to actuated condition and energization of the relay coil 59, an electrical circuit is established from supply line'50 through the on switch closed contacts 51, through lines 52 and 53, through the off switch now closed contacts 55, through line 58, through relay coil 59, and through line 60 to supply line 61. At the same time, an electrical circuit is also established from supply line 50 through the on switch contacts 51, through lines 52 and 54, through the relay now-closed contacts 57, through relay coil 59, and through line 60 to supply line 61.

The opening of the off switch normally closed contacts 56, as well as the opening of the relay normally closed contacts 63, interrupts the electrical circuit through line 62 to the solenoid coil 65 of water valve 26. Thus, water valve 26 is de-energized and biased to closed position, closing off the flow of water through water supply line 25 to the container 47.

When the filled container 47 and container holder 48 are removed from the container platform 21, the container platform will be resiliently urged upwardly as hereinbefore described, from the lower third position, reversely through the intermediate second position and finally to the upper first position, in other words, from the position of FIG. 1 to the position of FIG. 3. Of utmost importance to the principles of the present invention is the action of the electrical circuit of FIGS. 5 and 6 during this upward movement of the container platform 29, as related to the first movement of the off switch 28 from actuated to non-actuated condition upon movement of the container platform out of the lower third position, and the subsequent movement of the on switch 27 from actuated to non-actuated condition upon movement of the container platform reversely through the intermediate second position and finally into the upper first position.

With the electrical circuits established as described relative to the FIG. 6, and the solenoid coil 65 of water valve 26 de-energized so as to close this water valve, upward movement of the container platform 21 from the lower third position permits the off switch 28 to move from actuated to non-actuated condition, thereby opening the off switch normally open contacts 55 and closing the off switch normally closed contacts 56. Due to the fact, however, that the before described electrical circuit has been established through line 54 and the relay now-closed contacts 57 and through the relay coil 59, relay 24 remains energized and the solenoid coil 65 cannot be energized due to the relay now open contacts 63. This maintains the water valve 26 closed during this upward movement of the container platform 29 from the lower third position to the upper second position and prevents water from flowing from the water supply line 25, and this is despite the fact that the oif switch 28 has moved from actuated to non-actuated condition.

Thus, according to the principles of the present invention, a unique holding circuit is established preventing the usual spurt of water from the water supply line 25 encountered in the prior constructions of automatic container fillers when the container 47 and cup holder 48 are removed from the container platform 29 of these fillers.

In this return upward movement of the container platform 21, when the container platform passes through the intermediate second position, the on switch 27 is permitted to move from actuated to non-actuated condition so that the contacts 51 of this switch move to normally open position, thereby interrupting the entire electrical circuit from supply line 50. The relay coil 59 is, therefore, de-energized permitting the relay contacts 57 to move to normally open position and the relay contacts 63 to normally closed position.

Thus, when the container platform 21 finally reaches the upper first position, as shown in FIG. 3, the electrical circuit is again in the position of that shown in FIG. 5, ready for the beginning of the container filling cycle when a container 47 and container holder 48 are placed on the container platform.

This same unique holding function as described above for preventing the spurt of water from the water supply line 25 during the return upward movement of the container platform 21 upon removal of the filled container 47 and container holder 48 may be accomplished by a slightly modified form of electrical circuit and switch component, as is somewhat schematically illustrated in FIGS. 7 through 10. In this modified form,'the relay 24 and on off switches 27 and 28 are eliminated, with the switch means 23 taking on the form of a single snapaaction 3-position on-off switch 66, as shown for instance in FIG. 7.

Substitution of this single 3-position on-off switch 66 requires only very slight modification of the cup filler construction as described and shown in FIGS. 1 through 4, that is, very slight modification of the rearward end 39' of the container platform supporting arm 22 for actuation of merely a single switch 66 rather than the two switches 27 and 28, and also possibly a slight adjustment of the spring pressure exerted by the coil compression spring 33. Further, such snap-action 3- position on-Oflf switch 66 (FIG. 7) is a commercially available switch such as that known as Catalog Listing 9BS22 of Micro Switch, a division of Minneapolis- Honeywell Co.

As illustrated schematically in FIG. 7, the 3-position on-off switch 66 is formed by a stationary upper contact 67, an electrically conducting upper spring blade 68 having a contact 69, an electrically conducting lower spring blade 70 having a contact 71, and a stationary lower contact 72. As shown, the upper spring blade contact 69 projects upwardly for electrical connection with the stationary upper contact 67 and the lower spring blade contact 71 projects downwardly for electrical connection with the stationary lower contact 72, depending, of course, on the particular positioning of the upper and lower spring blades 68 and 70. Also, the secured ends of the upper and lower spring blades 68 and 70 spaced from contacts 69 and 71 are positioned permanently in electrical contact or connection.

In this modified form, when the container platform 21 is in its upper first position as shown in FIG. 3, the 3- position onofi switch 66 is in non-actuated off condition, as shown in FIG. 7, so that the electrical circuit through supply line 73, stationary upper contact 67, upper spring blade contact 69, upper spring blade 68, lower spring blade 70 and lower spring blade contact 71 is interrupted between this lower spring blade contact 71 and stationary lower contact 72. Thus, there is no electrical circuit into stationary lower contact 72, the solenoid coil 65 of water valve 26 and into supply line 74 For this reason, the solenoid coil 65 is not energized and the water valve 26 is closed, preventing the flow of water from the water supply line 25.

When the empty container 47 and container holder 48 are placed on the container platform 21, moving this container platform to the intermediate second position as shown in FIG. 4, the 3-position on-off switch 66 is moved by the pivotal container platform supporting arm 22 to an actuated on condition as shown in FIG. 8. In this actuated on condition, the lower spring blade 70 has been flexed by snap-action downwardly to place the lower spring blade contact 71 in electrical connection with the stationary lower contact 72,-while the upper spring blade 68 remains in its original position maintaining the upper spring blade contact 69 in electrical connection with the stationary upper contact 67.

Thus, the positioning of the 3-position on-off switch 66 in the actuated on condition as shown in FIG. 8 establishes an electrical circuit through supply line 73, stationary upper contact 67, upper spring blade contact 69, upper spring blade 68, lower spring blade 70, lower spring blade contact 71, stationary lower contact 72, the solenoid coil 65 of the water valve 26 and to supply line 74, thereby energizing the solenoid coil 65. Energization of solenoid coil 65 opens the water valve 26 and begins the flow of water from the water supply line 25 into the container 47.

When the water in the container 47 has reached the generally predetermined level 49, this increased weight of water has moved the container platform 21 downwardly to the lower third position as shown in FIG. 1, at which time, such movement moves the 3-position onoff switch 66 by snap-action to the actuated off condition as shown in FIG. 9. In this actuated off condition of switch 66, the upper spring blade 68 has flexed by snap-action downwardly against the lower spring blade 70, thereby interrupting the electrical connection between the upper spring blade contact 69 and the stationary upper contact 67, interrupting the electrical circuit through this switch and de-energizing the solenoid coil 65.

De-energization of the solenoid coil 65 permits the water valve 26 to be biased to closed position. This stops the flow of water through the Water supply line 25 and into the container 47.

As the filled container 47 and container holder 48 are removed from the container platform 21, the container platform is urged upwardly, moving upwardly from the lower third position shown in FIG. 1 reversely through the intermediate second position shown in FIG. 4 to finally arrive at the upper first position shown in FIG. 3. Further, during this upward movement of the container platform, the 3-position on-off switch 66 is formed such that both the upper and lower spring blades 68 and 70 will flex by snap-action upwardly together, as illustrated in FIG. 10.

This means that as soon as the container platform 21 begins to move upwardly away from the lower third position, the lower spring blade contact 71 leaves the stationary lower contact 72 immediately and prior to the upper spring blade contact 69 coming to rest in electrical connection with the stationary upper contact 67. Thus,

this 3-position on-off switch 66 is arranged to move reversely directly from the actuated oif condition to the non-actuated off condition, and there is never an electrical circuit re-established through the switch during this reverse movement.

This further means that during the reverse upward movement of the container platform 21 from the lower third position shown in FIG. 1 through the intermediate second position shown in FIG. 4 to the upper first position shown in FIG. 3, the water valve 26 will remain closed, preventing any water flow in the water supply line 25. Finally, when the upper and lower spring blades 68 and 70 have completed the snap-action upwardly and rest against the stationary upper contact 67, the 3-position on-ofi' switch 66 will be in the non-actuated off condition as shown in FIG. 7, ready for the filling cycle to again be started by the placing of an empty container 47 and container holder 48 on the container platform 21.

Thus, according to this modified form of the automatic container filler construction of the present invention, a holding means is again provided in the electrical circuit through the inherent construction and arrangement of the 3-position on-oif switch 66 for preventing the objectionable spurt of water from the water supply line 25 when the filled container 47 and container holder 48 are removed from the container platform 21.

It should :be understood that the snap-action 3-position on-off switch 66 is merely one of at least several of this type of switch available on the commercial market for "accomplishing this holding function previously described through the mechanical structure thereof, either internally or externally, and it is not in tended to limit the principles of the present invention to the particular switch schematically illustrated and described.

Furthermore, it should be understood that most of these switches such as the on and ofl switches 27 and 28, or the 3-position on-off switch 66, are resiliently urged through the mechanical structure thereof to non-actuated condition, which may provide normal resilient urging of the container platform 21 toward the upper first position. For this reason, under certain conditions, these switches may supplement, require modification or, or even completely eliminate the coil compression spring 33, all of which is intended within the scope of the present invention.

In the foregoing description, certain terms have been used for brevity, clearness and understanding but no unnecessary limitations are to be implied therefrom, because such words are used for descriptive purposes herein and are intended to be broadly construed.

Moreover, the embodiments of the improved construction illustrated and described herein are by Way of example and the scope of the present invention is not limited to the exact details of construction shown.

Having now described the invention, the construction, operation and use of preferred embodiments thereof, and the advantageous new and useful results obtained thereby,

1 1 the new and useful construction and reasonable mechanical equivalents thereof obvious to those skilled in the art are set forth in the appended claims.

We claim:

1. Automatic container filler construction for dental units and the like of the type in which a container platform upon which a container may be positioned is mounted on a frame movable between an upper first position and an intermediate second position and a lower third position, in which the container platform is mounted normally biased to the upper first position in the absence of a container thereon, in which the container platform will move to intermediate second position as a result of the container being positioned thereon, in which the container platform will move to lower third position as a result of the container being filled with Water to a generally predetermined level, in which a water line is provided with a water valve operably connected therein with the valve being normally biased to closed position and electrically actuated to open position, and in which the water line is mounted positioned for directing Water into the container when the container is positioned on the container platform and the water valve is electrically actuated to open position; the improvements including an electrical circuit operably connected through the water valve for electrically actuating the valve to open position upon the electrical circuit being closed and permitting the valve to be biased to closed position upon the electrical circuit being opened, a snap-action 3-position onoff switch operably connected in the electrical circuit, said switch comprising a stationary upper contact, a stationary lower contact spaced therefrom, an electrically conducting upper spring blade having a contact at one end for contact with the stationary upper contact, an electrically conducting lower spring blade having a contact at one end for contact with the stationary lower contact, the opposite ends of the spring blades being positioned permanently in electrical contact with each other spaced from the stationary upper and lower contacts, a pivoted platform supporting arm having one end fixed to said container platform and the other end openably engaging the switch for actuating the switch upon movement of the container platform, the switch being constructed and arranged for opening the electrical circuit when the container platform is in upper first position and for closing the electrical circuit when the container platform is moved from upper first to intermediate second position, and for opening the electrical circuit when the container platform is moved from intermediate second to lower third position, and for maintaining the electrical circuit open during return movement of the container platform from lower third to upper first position, so that placing of a container on the container platform will move the platform from upper first to intermediate second position to open the water valve :and begin the flow of water into the container, the filling of the container will move the container platform from intermediate second to lower third position to close the water valve and stop the flow of water into the container, and removal of the filled container from the container platform will permit the platform to return from lower third to upper first position while the water valve remains closed.

2. Automatic container filler construction as defined in claim 1, in which the contact ends of the spring blades are located together in contact with the upper stationary contact and spaced from the lower stationary contact when the container platform is in the upper first position in which the contact on the upper spring blade engages the upper stationary contact and the contact on the lower spring blade engages the lower stationary contact in the intermediate second position of the container platform, in which the contacts upon the spring blades engage each other in contact with the lower stationary contact and are spaced from the upper stationary contact when the container platform is in the lower third position, and in which the contacts upon the spring blades engage each other and are spaced from both the upper and lower stationary contacts as the container platform returns from lower third position to upper first position.

References Cited by the Examiner UNITED STATES PATENTS 616,862 12/1898 Richards 1771 17 616,864 12/1898 Richards 177117 2,763,457 9/1956 Gregory 1771 17 3,082,832 3/1963 Mitthauer et al 177--l 17 RICHARD B. WILKINSON, Primary Examiner.

R. S. WARD, JR., Assistant Examiner. 

1. AUTOMATIC CONTAINER FILLER CONSTRUCTION FOR DENTAL UNITS AND THE LIKE OF THE TYPE IN WHICH A CONTAINER PLATFORM UPON WHICH A CONTAINER MAY BE POSITIONED IS MOUNTED ON A FRAME MOVABLE BETWEEN AN UPPER FIRST POSITION AND AN INTERMEDIATE SECOND POSITION AND A LOWER THIRD POSITION, IN WHICH THE CONTAINER PLATFORM IS MOUNTED NORMALLY BIASED TO THE UPPER FIRST POSITION IN THE ABSENCE OF A CONTAINER THEREON, IN WHICH THE CONTAINER PLATFORM WILL MOVE TO INTERMEDIATE SECOND POSITION AS A RESULT OF THE CONTAINER BEING POSITIONED THEREON, IN WHICH THE CONTAINER PLATFORM WILL MOVE TO LOWER THIRD POSITION AS A RESULT OF THE CONTAINER BEING FILLED WITH WATER TO A GENERALLY PREDETERMINED LEVEL, IN WHICH A WATER LINE IS PROVIDED WITH A WATER VALVE OPERABLY CONNECTED THEREIN WITH THE VALVE BEING NORMALLY BIASED TO CLOSED POSITION AND ELECTRICALLY ACTUATED TO OPEN POSITION, AND IN WHICH THE WATER LINE IS MOUNTED POSITIONED FOR DIRECTING WATER INTO THE CONTAINER WHEN THE CONTAINER IS POSITIONED ON THE CONTAINER PLATFORM AND THE WATER VALVE IS ELECTRICALLY ACTUATED TO OPEN POSITION; THE IMPROVEMENTS INCLUDING AN ELECTRICAL CIRCUIT OPERABLY CONNECTED THROUGH THE WATER VALVE FOR ELECTRICALLY ACTUATING THE VALVE TO OPEN POSITION UPON THE ELECTRICAL CIRCUIT BEING CLOSED AND PERMITTING THE VALVE TO BE BIASED TO CLOSED POSITION UPON THE ELECTRICAL CIRCUIT BEING OPENED, A SNAP-ACTION 3-POSITION "ONOFF" SWITCH OPERABLY CONNECTED IN THE ELECTRICAL CIRCUIT, SAID SWITCH COMPRISING A STATIONARY UPPER CONTACT, A STATIONARY LOWER CONTACT SPACED THEREFROM, AN ELECTRICALLY CONDUCTING UPPER SPRING BLADE HAVING A CONTACT AT ONE END FOR CONTACT WITH THE STATIONARY UPPER CONTACT, AN ELECTRICALLY CONDUCTING LOWER SPRING BLADE HAVING A CONTACT AT ONE END FOR CONTACT WITH THE STATIONARY LOWER CONTACT, THE OPPOSITE ENDS OF THE SPRING BLADES BEING POSITIONED PERMANENTLY IN ELECTRICAL CONTACT WITH EACH OTHER SPACED FROM THE STATIONARY UPPER AND LOWER CONTACTS, A PIVOTED PLATFORM SUPPORTING ARM HAVING ONE END FIXED TO SAID 